Cathode ray tube



Aug. 6, 1935. W Q COOUDGE 2,010,712

CATHODE RAY TUBE Filed Sept. 23, 1930 Inv'entof: WiHar D. Coolidge,

* Hts Attornerg.

aperture 27. 'I'he window is pressed with the soldered side against the cap piece and a small flame played about the periphery to melt the solder 2l, thereby hermetically sealing the Window to the cap. Solder may also be applied between the inner surface of the window and the outer periphery of the cap piece as indicated by reference character 28 which, in addition to the layer of solder 2| holds the Window securely to the anode. The solder 28 is applied with the minimum amount of non-corrosive flux as in the case of solder 2 I.

The tube may then be finished and exhausted in the usual manner. The grooved portion has a diametral size corresponding to that of the aperture 2l so that the cathode rays which go through the opening are obstructed in a large degree only by the thin sections of metal. In the case of parallel grooves, the cathode stream emerges as sheets of rays in parallel planes and separated from each other by the thickness of each land or projection.

As a modified construction, I may employ the arrangement shown in Fig. 7 in which the window is obtained by counter-boring a solid aluminum or other light metal member 30 and leaving a thin section of metal 3i which is attached by butt-Welding to a heavy flanged cap piece 32 made of copper and secured to the end of the tubular anode 5 by solder as in the previous construction. This modification offers some advantage over that shown in the other figures in that the window is an integral part of the cap member and the rings of solder 9' and 2| are not necessary. Moreover, the solder which secures members 5 and 32 together is far removed from the window position.

While I have described my invention more particularly with reference to aluminum, it will be understood that the process of grooving or otherwise producing thin localized sections of metal to oder facility of traverse to an electron stream is applicable to all metals, also to non-metallic materials. However, I prefer to employ metals, particularly those of low speciiic gravity on account of their ready transparency to cathode rays.

It is evident that my invention is not limited to any specic form or shape of groove but includes surface indentations and deformations of all kinds and shapes whereby certain portions of a window which ordinarily would be impenetrable to cathode or other rays are rendered penetrable in a substantial degree.

In will also be understood that the use of integral ribs and projections for strengthening the window, as described hereinbefore, does not preclude the employment of additional supporting a structure where necessary in the case of large windows. Indeed, the ribs, particularly those of rectangular section, lend themselves readily to the use of ordinary supporting grids which may abut that surface of the ribs, the furthermost removed from the thin portion of the window. An extensive window may thus be supported in two lateral directions, if desired, in one direction, by the parallel ribs and in another direction, preferably normal thereto, by the grid on which the ribs rest. Furthermore, the invention is not limited to cathode ray propagation but is suiciently broad to cover electrical rays oi all wave lengths including X-rays, also alpha rays, which have to pass through a window of a tube in which such rays are generated.

What I claim as new and desire to secure by Letters Patent of the United States, iszl. An electric discharge device comprising an evacuated envelope, a cathode and an anode therein cooperating to produce cathode rays, a metal window secured to the envelope and electrically connected to the anode, said window being a single sheet of material provided with alternate and integral relatively thin and relatively thick portions, the thin portions allowing ready penetration of the material by the rays.

2. An electric discharge device comprising an evacuated envelope, a cathode and an anode therein cooperating to produce cathode rays, a corrugated metal Window secured to the envelope and electrically connected to the anode, said window being a single sheet of material and the metal at the bottom of the corrugations being suciently thin to offer the minimum practical amount of obstruction to the passage of the rays.

3. An electric discharge device comprising an evacuated envelope, a cathode and a hollow anode therein cooperating to produce cathode rays, said anode terminating in a metal Window, said window being a single sheet of material provided with parallel lands and grooves of rectangular section, the thickness of material at the bottom of the grooves being suiciently small to allow ready passage of the electrons therethrough.

4. An electric discharge device comprising an evacuated envelope, a cathode and an anode therein cooperating to produce cathode rays, a metal Window secured to the envelope and electrically connected to the anode, said Window being a single sheet of material provided with parallel lands and grooves, and having a thickness at the bottom of the groove of less than onehalf mil.

5. An electric discharge device comprising an envelope, a cathode and a hollow cylindrical anode therein cooperating to produce an electron stream, said anode being hermetically closed by a Window consisting of metal of relatively low specific gravity and being a single sheet of material provided with integral strengthening ribs.

6. A Window for an electric discharge device, said window being fabricated of aluminum and being a single sheet of material provided with a plurality of integral strengthening ribs.

WILLIAM D. COOLIDGE. 

